Peer-to-peer network system with manageability

ABSTRACT

A peer-to-peer network system provides at least one peer with information for configuration of a peer-to-peer network to optimize the configuration of the peer-to-peer network by using at least one of information about a status of the at least one peer, information about a status of an underlying network and information about a user in respect of services.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2012-0075042, filed Jul. 10, 2012, the disclosure ofwhich is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to a peer-to-peer network system, and moreparticularly to, a peer-to-peer network system with manageabilityimproving quality of peer-to-peer network-based services and providing aservice provider with service management functions.

This research was supported by the Context-Aware Contents DeliveryStandardization program of MKE (The Ministry of Knowledge Economy)

2. Discussion of Related Art

A peer-to-peer network in association with content services forproviding a plurality of recipients with content refers to a distributednetwork where a plurality of individual participants called peers do notreceive content from a specific server but are directly connected toeach other and transmit/receive content with each other. Therefore, asingle peer functions as a client receiving content and may function asa server providing content as a need arises. In addition, since apeer-to-peer network is formed using a construction algorithm on thebasis of content to be shared rather than a specific server, inter-peerconnections may be flexible, and network size may also vary.

In terms of content services, when selecting a peer that sends content,a peer-to-peer network does not consider the status of an underlyingphysical network and information on peers constituting the peer-to-peernetwork. Therefore, efficiency in constructing the peer-to-peer networkmay be reduced, and load may be concentrated on a specific network or aspecific peer. In addition, service quality may not be uniform inrespect of services, and it may be difficult to prevent illegaldistribution of content.

SUMMARY OF THE INVENTION

The present invention is directed to a peer-to-peer network system withmanageability collectively considering the status of an underlyingnetwork and the status of a peer.

One aspect of the present invention provides peer-to-peer network systemwith manageability, including: at least one peer, wherein thepeer-to-peer network system provides the at least one peer withinformation for configuration of a peer-to-peer network to optimize theconfiguration of the peer-to-peer network by using at least one ofinformation about a status of the at least one peer, information about astatus of an underlying network and information about a user in respectof services, and the peer-to-peer network system allows a serviceprovider to stably provide service to the at least one peer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent to those of ordinary skill in the art bydescribing in detail exemplary embodiments thereof with reference to theattached drawings in which:

FIG. 1 is a diagram illustrating a system configuration of apeer-to-peer network in a domain view according to an exemplaryembodiment of the present invention;

FIG. 2 is a schematic diagram illustrating entities constituting apeer-to-peer network according to an exemplary embodiment of the presentinvention;

FIG. 3 is a diagram illustrating interoperation relationships between auser profile management server and related entities in a peer-to-peernetwork system according to an exemplary embodiment of the presentinvention;

FIG. 4 is a diagram illustrating interoperation relationships between apeer activity management server and related entities in a peer-to-peernetwork system according to an exemplary embodiment of the presentinvention;

FIG. 5 is a diagram illustrating interoperating relationships between anoverlay management server and related entities in a peer-to-peer networksystem according to an exemplary embodiment of the present invention;

FIG. 6 is a diagram illustrating interoperation relationships between anetwork information management server and related entities in apeer-to-peer network system according to an exemplary embodiment of thepresent invention;

FIG. 7 is a diagram illustrating operation relationships between a peerand related entities in a peer-to-peer network according to an exemplaryembodiment of the present invention;

FIG. 8 is a diagram illustrating interoperation between an index serverand related entities in a peer-to-peer network system according to anexemplary embodiment of the present invention;

FIG. 9 is a diagram illustrating interoperation relationships between acache server and related entities in a peer-to-peer network systemaccording to an exemplary embodiment of the present invention; and

FIG. 10 is a block diagram illustrating interoperation relationshipsbetween a relay server and related entities in a peer-to-peer networksystem according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. This invention may, however, be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. In drawings, portions unrelated todescription will be omitted to distinctly describe the present inventionand similar reference numerals are labeled to similar portionsthroughout the specification.

FIG. 1 is a diagram illustrating a system configuration of apeer-to-peer network in a domain view according to an exemplaryembodiment of the present invention. Referring to FIG. 1, a peer-to-peernetwork system with manageability according to an exemplary embodimentof the present invention may include a peer-to-peer Service Provider(P2PSP) domain, an Internet Service Provider (ISP) domain and a Userdomain.

The P2PSP domain may control and support managed P2P-based services. TheP2PSP domain may control service in cooperation with various serverssuch as an overlay management server 140, a user profile managementserver 110, a peer activity management server 120 and an index server130 to be described below. In addition, the P2PSP domain may supportservice through a cache server 160 and a relay server 170. In addition,according to the present invention, the P2PSP domain may improve managedP2P-based service in terms of underlying network efficiency incooperation with an Internet service provider (ISP).

The ISP domain may provide another domain, such as the P2PSP or userdomain, with information on the underlying network, such as capacity,policy and network distance. The ISP domain may include a underlyingnetwork information server (UNIS) 150 as an entity providing suchinformation.

The user domain is a domain where the managed P2P-based servicesaccording to an exemplary embodiment of the present invention areconsumed. The user domain may include one or more peers. Peers mayreceive service from another peer or an entity in the P2PSP domain. Inaddition, a peer may function as the cache server 160 or the relayserver 170 according to network policies or needs.

As illustrated in FIG. 1, since a peer-to-peer network system withmanageability according to an exemplary embodiment of the presentinvention may further include the P2PSP domain and the ISP domain inaddition to the user domain consisting of peers, disadvantages of aconventional peer-to-peer network may be overcome, and quality ofnetwork service and manageability of a service provider may be moreimproved. In addition, each domain as illustrated in FIG. 1 may includepeers or various servers. A server or a peer exemplified in thespecification may be collectively referred to as an entity. Hereinafter,functions of entities and inter-entity interactions according to anexemplary embodiment of the present invention will be described indetail.

FIG. 2 is a schematic block diagram illustrating entities in apeer-to-peer network system according to an exemplary embodiment of thepresent invention. Referring to FIG. 2, a peer-to-peer network systemaccording to an exemplary embodiment of the present invention mayinclude at least one peer 200 and a plurality of servers 110, 120, 130,140, 150, 160 and 170 that join a peer-to-peer network andtransmit/receive content. The plurality of servers may include the userprofile management server 110, the peer activity management server 120,the index server 130, the overlay management server 140, an underlyingnetwork information management server 150, the cache server 160 and therelay server 170 according to functions.

The user profile management server 110 may manage user information suchas user name, identification (ID), personal information or service usagestatus, for functions in service aspects such as charging for service byusing information in respect of services to be described below. Inaddition, the user profile management server 110 may provide the userinformation to other entities. The user profile management server 110may create a peer-to-peer user profile in order to manage the userinformation and may update or provide the peer-to-peer user profile to arequester that needs the peer-to-peer user profile, for example, anoverlay management server to be described below. Therefore, a profilefor each user may be maintained in the user profile management server110. User information in a user profile may include user identification(ID), network information and user reputation. In addition, the userprofile management server 110 may include user information managementfunctions to perform the corresponding functions.

The peer activity management server 120 may manage information aboutpeers to be described below in order to efficiently construct apeer-to-peer network. The peer activity management server 120 maycreate, collect or manage status information about the peers, analyzethe status information and provide information to the overlay managementserver 140. Information collected by the peer activity management server120 may include dynamic status information or static status informationabout the peers. In addition, the peer activity management server 120may include peer activity information management functions in order toperform the above-described functions.

The index server 130 may provide and manage meta information aboutcontent necessary for a user to receive service. The index server 130may manage meta information about content and mapping informationbetween the content and an overlay network. The index server 130 mayprovide a user with necessary meta information and provide a peer, whichneeds service, with information about the overlay management server 140that the peer is to connect in order to receive the service. Though theindex server 130 may provide only meta information about content, themeta information may include the information about the overlaymanagement server 140 that the peer is to connect. The index server 130may include content information management functions in order to performthe corresponding functions.

The overlay management server 140 may provide and manage informationabout the peer-to-peer network so that peers may construct thepeer-to-peer network. The overlay management server 140 may generate andmanage the information about the peer-to-peer network constructed toprovide the content on the basis of the user information in respect ofservices, status information about an underlying network with respect tothe peer-to-peer network, and peer status information. In addition, theoverlay management server 140 may manage a list of peers joining eachoverlay network. When new peers join the corresponding overlay networkand request a peer list, the overlay management server 140 may interworkwith the peer activity management server 120 and the network informationmanagement server 150 to create and transmit an optimal peer list to thepeers. The overlay management server 140 may include overlay networkmanagement functions that manage the overlay network and overlayresource management functions that manage resources in the overlaynetwork, and track and maintain status information.

The network information management server 150 may manage the informationabout the underlying network in order to construct the peer-to-peernetwork that reflects the information about the underlying network andmay provide another entity with the information. The network informationmanagement server 150 is present in the ISP domain and may performexclusive functions for providing the information about the underlyingnetwork and information about network management policies to a peer or aserver in another domain such as the P2PSP domain or the user domain.The network information management server 150 may provide networkdistance information between the peers in the peer-to-peer network. Thenetwork information management server 150 may interact with the peers orthe overlay management server 140. More specifically, the networkinformation management server 150 may include network informationmanagement functions in order to perform the corresponding functions.The network information management functions may interact with theoverlay management server 140 in order to provide the information aboutthe underlying network to the overlay management server 140. Theinformation about the underlying network may be selectively provided tothe peers.

The cache server 160 may download or distribute content in place of apeer that does not have sufficient resources or is lack of resources. Inother words, the cache server 160 may temporarily cache (or store)content in place of a peer in order to stably provide P2P-basedservices. The cache server 160 may include an exclusive server providedby the P2PSP in order to perform the corresponding functions.Alternatively, a peer that provides content may voluntarily serve as atemporary device that offers the corresponding functions. When the cacheserver 160 includes an exclusive cache server, the exclusive server isgenerally a trusted device that is controlled by the P2PSP. Therefore,when a trouble occurs, the cache server 160 is required to report thetrouble to the overlay management server 140. When the cache server 160includes a temporary cache device, the temporary cache device isgenerally a user device that has less responsibility than the exclusivecache server. Therefore, when a trouble occurs, the cache server 160 isrecommended to report the trouble to the overlay management server 140.

The cache server 160 may be functions configured to perform thecorresponding function. The cache server 160 may include cache serverresource management functions, meta information management functions,resource virtualization functions, overlay network management peerfunctions and peer activity management functions. The above-describedfunctions may manage inter-peer connections, registration of aparticular service and activity information to be reported.

In addition, the cache server 160 may include data exchange functionsand buffermap management functions as data management functionsconfigured to perform the corresponding function. The data managementfunctions may manage data exchange between a local buffer and anotherpeer (or cache server or relay server).

The relay server 170 may relay content in order to help a peer, whichdid not participate in the peer-to-peer network due to a firewallaccording to the status of the network, join the network. For example,the relay server 170 may help a specific peer stably access the networkby maintaining connections to the corresponding peer present behind aNAT/firewall. Therefore, the relay server 170 may not activelyparticipate in the peer-to-peer overlay network but improve a networkconnection rate and connection quality of a peer. The relay server 170may be comprised of an exclusive server provided by the P2PSP in orderto perform the corresponding functions, or a temporary device to which apeer providing content voluntarily provides the corresponding functions.When the relay server 170 is comprised of an exclusive server, the relayserver 170 is generally a trusted device that is controlled by theP2PSP. Therefore, when a trouble occurs, the relay server 170 isrequired to report the trouble to the overlay management server 140.When the relay server 170 is comprised of a temporary relay device, therelay server 170 is a user device that has less responsibility than theexclusive relay server. Therefore, when a trouble occurs, the relayserver 170 is recommended to report the trouble to the overlaymanagement server 140.

The relay server 170 may include relay server resource managementfunctions and peer activity management functions as functions configuredto perform the corresponding function. The functions may manageinter-peer connections, registration of specific service, relayinformation and activity status to be reported as activity information.

In addition, the relay server 170 may include data relay functions asdata management functions configured to perform the correspondingfunction. The data management functions may manage data exchange betweena local buffer and another peer (or cache server or relay server).

FIG. 3 is a diagram illustrating interoperation relationships between auser profile management server and related entities in a peer-to-peernetwork system according to an exemplary embodiment of the presentinvention. Referring to FIG. 3, the user profile management server 110may include user information management functions configured to manageuser profile information.

The user information management functions may manage and control profileinformation about a user and information relevant to user's activity andprovide user information in respects of service to the overlaymanagement server 140.

When the user information management functions manage the profileinformation about the user, the user information management functionsmay manage data in a non-automatic manner. For example, the userinformation management functions may perform operations such as creatingand deleting a user's ID and changing information, in a user-drivenmanner.

The user profile information may, for example, user priority, userpreference, user state, contribution status and service usage.

While the user information management functions maintain and manage theuser profile information as information for a user profile, if the userprofile information is determined as peer profile information, the userinformation management functions may change the correspondinginformation to the peer profile information and maintain the peerprofile information. The peer profile information may include networklocations, connection types of a peer, a communication method, such asADSL, Cable, or FTTH, and a type of a device forming a peer. The peerprofile information maintained by the user information managementfunctions may be transmitted to the peer activity management server 120and managed by the peer activity management server 120.

Information relevant to user activity may include information about arecord of user's service usage or information about a record of user'sproviding service. The information relevant to the user activity may bereceived from the peer activity management server 120 and utilized asincentives for the user.

As illustrated in FIG. 3, the user profile management server 110 maycommunicate with the overlay management server 140 to generate userprofile information and may communicate with the peer activitymanagement server 120 to obtain activity information about a specificpeer. In addition, when there is a request from an external entity, theuser profile management server 110 may provide and update informationrelevant to user activity or the user profile information being managed.

In other words, the peer-to-peer network system according to anexemplary embodiment of the present invention may add manageabilityusing user information in respect of services on the basis ofinformation managed and provided by the user profile management server110, thereby ensuring network reliability and providing servicestability and differentiation.

FIG. 4 is a diagram illustrating interoperation relationships between apeer activity management server 120 and related entities in apeer-to-peer network system according to an exemplary embodiment of thepresent invention. Referring to FIG. 3, the peer activity managementserver 120 may include peer activity information management functionsand manage peer activity information. The peer activity managementserver 120 may receive information from peers, create and manage peerstatus information on the basis of the information, and transmit thepeer status information at the request of another server or peer.

The peer status information managed by the peer activity managementserver 120 may include dynamic status information related to peeractivity status and static status information including peer profileinformation such as network construction and network service policies.The peer activity status information may be collected from peers, andthe collected information may be analyzed, processed and stored.

The peer activity information managed by the peer activity managementserver 120 may include peer dynamic status information. Since the peerdynamic status information varies over time, the peer dynamic statusinformation may be deleted or changed and maintained according to apredetermined cycle, at a predetermined event, or according topredetermined conditions such as network service policies.

The peer dynamic status information may include physical network statusinformation, overlay network status information and system statusinformation.

The physical network status information may include incoming bandwidthand outgoing bandwidth and refer to snapshot information about thecurrent physical network status of a peer.

The overlay network status information may be snapshot information aboutpeer's current overlay network, which may include information aboutconnected peers, the amount of data transmitted to a specific peer andthe amount of data received.

The system status information may be peer's current physical systemstatus information, which may include system load and storage status.

The dynamic status information may be reported by peers and collected.Since the dynamic status information is periodically or aperiodicallytransmitted, the dynamic status information may not be dominated at all.The peer activity management server 120 may not directly request a peerfor corresponding information but may be operated in such manual modethat the peer activity management server 120 may collect and manage onlythe information transmitted from the peer.

Status information that the peer periodically reports to the peeractivity management server 120 may include, for example, informationabout the amount of data the peer received from other peers, the amountof data transmitted, and an operation history such as a datatransmission/reception history. Information that the peer aperiodicallyreports to the peer activity management server 120 is about apredetermined event when the predetermined event occurs. For example,the information may include an error report that is immediately sent ifa trouble occurs when the peer accesses another peer.

In addition, the peer activity management server 120 may manage the peerprofile information. The peer profile information may refer toinformation that is set in an application in order for each peer tooperate as a peer in the peer-to-peer network. For example, the peerprofile information may include information such as limiting a maximumupload capacity to x Mbps or limiting a maximum download capacity to yMbps and setting a maximum number of peer connections to n. Since thepeer profile information is based on initial setup of the peer, the peerprofile information may be referred to as static status information.However, the setup may be changed. The peer profile information may alsobe subject to change according to changes in network policies or nnetwork status.

The peer profile information may be classified into information about aP2P behavior policy. The P2P behavior policy may be classified into amaximum number of peer connections, a maximum number of peer connectionsper overlay network, a maximum upload capacity and a maximum downloadcapacity.

As access information of the peer activity management server 120 usedwhen each peer provides its profile information to the peer activitymanagement server 120, for example, address information, the peer staticstatus information may be requested and received from the overlaymanagement server 140 when each peer joins an overlay network.

The peer static status information may be voluntarily provided by thepeer and may be used as peer incentives. In addition, the peer activitymanagement server 120 may be operated in such manual mode that the peeractivity management server 120 may not directly request the peer for thecorresponding information, and collect and manage only the informationtransmitted from the peer.

In addition, the peer activity management server 120 may analyze andprocess dynamic status information and static status informationcollected from peers. The analyzed peer activity information may bedivided into dynamic status information or static status informationaccording to type, and may be maintained.

When the peer activity management server 120 needs to transmit the peeractivity information to the overlay management server 140, the peeractivity management server 120 may extract and analyze necessaryinformation, process the information in a format suitable fortransmission and transmit the information to the overlay managementserver 140.

The overlay management server 140 may update overlay network statusinformation in order to keep the status of the overlay network, managedby the overlay management server 140, up to date. More specifically, theoverlay management server 140 may request the peer activity managementserver 120 for status information about peers joining the overlaynetwork. The requested information may be status information about allof the peers or status information about some of the peers. The peeractivity management server 120 may respond to the request on the basisof the information that the activity management server 120 has.Information may be transmitted from the peer activity management server120 to the overlay management server 140 at the request of the overlaymanagement server 140 and by notification from the peer activitymanagement server 120. Upon request from the overlay management server140, interfaces of the overlay management server 140 and the peeractivity management server 120 may be used. By notification from thepeer activity management server 120, a channel is to be establishedbetween the overlay management server 140 and the peer activitymanagement server 120 in order to transmit the notification. Therefore,subscription between both servers 120 and 140 may precede. Morespecifically, subscription may be performed by the interfaces of bothservers 120 and 140. Information transmitted/received during asubscription process may be analyzed and processed by the peer activitymanagement server 120.

As illustrated in FIG. 4, the peer activity management server 120 mayanalyze and process information collected from the peer 200 and maintainthe information as peer activity information. At the request of theoverlay management server 140, the activity management server 120 mayprovide the peer activity information. When the user profile managementserver 110 requests activity information about the peer, the activitymanagement server 120 may provide the requested activity information.

FIG. 5 is a diagram illustrating interoperating relationships between anoverlay management server and related entities in a peer-to-peer networksystem according to an exemplary embodiment of the present invention.Referring to FIG. 5, the overlay management server 140 may includeoverlay management functions 141 that manage an overlay network andoverlay resource management functions 142 that manage resources in theoverlay network, and track and maintain status information.

The overlay network management functions 141 may manage overlayinformation in order to manage the overlay network and manageinformation to construct the peer-to-peer network, for example, a listof peers in order to optimally construct the overlay network in thepeer-to-peer network. In addition, the overlay network managementfunctions 141 may provide the information to construct the peer-to-peernetwork to another entity in the peer-to-peer network system.

The overlay network management functions 141 may maintain theinformation about the plurality of overlay networks and the peerinformation about the peers joining each of the overlay networks inorder to manage the plurality of overlay networks. The networkmanagement functions 141 may be generally formed in a database format.The information about an overlay network that the overlay networkmanagement functions 141 maintain may be about characteristics of eachoverlay network, such as an overlay network ID, a seeder, a leecher, arelay server, a cache server and effective time. The overlay networkmanagement functions 141 may maintain information about peers joiningeach corresponding overlay network, such as IP, port and peer ID.

The overlay network management functions 141 may process a request froma peer, such as joining or leaving an overlay network. For example, whena peer sends a request to join an overlay network to the overlaymanagement server 140, the overlay network management functions 141 mayrequest the user profile management server 110 for necessary informationto check whether or not the peer sending the request is qualified tojoin the corresponding overlay network.

The overlay network management functions 141 may manage a peer list asinformation to optimally construct a network. For example, when aspecific peer requests a peer list of peers in an overlay network, theoverlay network management functions 141 may create and provide anoptimal peer list in consideration of the network the peer joins andstatuses of other peers. When creating the peer list, the overlaynetwork management functions 141 may receive the information about theunderlying network from the network information management server 150and receive the peer activity information from the peer activitymanagement server 120.

The overlay network management functions 141 may receive the informationabout the peer activity from the peer activity management server 120.Here, an authentication procedure may precede between the overlaymanagement server 140 and the peer activity management server 120 inorder to ensure a security channel.

The overlay network management functions 141 may communicate with thenetwork information management server 150 and transmit the informationabout a request peer and the peer list of the peers in the overlaynetwork to the network information management server 150 in order toreceive the information about the underlying network. The networkinformation management server 150 may arrange the peers in the peer listby using cost information between the request peer and the peers in thepeer list and transmit the arranged peer list to the overlay managementserver 140.

The overlay network management functions 141 may interwork with the peerand process a response to a peer's request such as joining or leavingfrom a network. At this time, the overlay management server 140 maytransmit information about the cache server 160 and the relay server 170and the peer activity management server 120 related to the overlaynetwork.

The overlay resource management functions 142 may manage resourceinformation related to construction of a peer-to-peer network, that is,resource information of the cache server 160 and the relay server 170managed by the P2PSP. More specifically, the overlay resource managementfunctions 142 may maintain information about to which overlay networkeach resource is allocated to or how each resource is utilized in orderto maintain resource usage status information according to the cacheserver 160 and the relay server 170.

A user may request the overlay management server 140 for resources ofthe cache server 160 and the relay server 170. More specifically, theuser may request these resources when a content owner constructs anoverlay network in order to distribute content, when a service providerconstructs an overlay network, or when a general user requests the cacheserver 160 to receive content for the general user. Since the overlaymanagement server 140 carries out overall control of resources, ageneral peer may not access the resources of the cache server 160 andthe relay server 170.

The resources of the cache server 160 and the relay server 170 may bedirectly operated by the P2PSP. However, when a general peer serves asthe cache server 160 or the relay server 170, corresponding resourcesmay be provided from the general peer. In the latter case, when a peeraccesses the overlay management server 140, the peer may designate andregister its operation mode.

The overlay resource management functions 142 may manage overlayresource information. More specifically, the overlay resource managementfunctions 142 may manage information related to the resources of thecache server 160 and the relay server 170 managed by the overlaymanagement server 140. For example, the overlay resource managementfunctions 142 may maintain information about available resource statusand usage status of the cache server 160 and the relay server 170.

The overlay resource management functions 142 may control overlayresource information. For example, the overlay resource managementfunctions 142 may reserve the corresponding resources with respect tothe cache server 160 and the relay server 170. In this case, the overlayresource management functions 142 may control the cache server 160 sothat the cache server 160 may join a specific overlay network to provideservice and may designate allocated resources of the cache server 160.Attributes of the allocated resource of the cache server 160 may includeuplink bandwidth, downlink bandwidth and the maximum number ofconcurrent users. Since the cache server 160 operates as a virtual peer,the cache server 160 may be expressed as a subset of a peerconfiguration.

The overlay resource management functions 142 may control the relayserver 170 so that the relay server 170 may join a specific overlaynetwork to provide service and may designate allocated resources of therelay server 170. Attributes of the allocated resources of the relayserver 170 may include uplink bandwidth, downlink bandwidth, the maximumnumber of concurrent users and allocated overlay network information.Since the relay server 170 does not store data but receives andtransfers the data, the relay server 170 does not operate as a virtualpeer unlike the cache server 160.

In FIG. 5, the cache server 160 and the relay server 170 are notillustrated as entities interworking with the overlay management server140. However, the cache server 160 and the relay server 170 mayinterwork with the cache server 160 and the relay server 170 in order tocontrol and manage resources.

FIG. 6 is a diagram illustrating interoperation relationships betweenthe network information management server 150 and related entities in apeer-to-peer network system according to an exemplary embodiment of thepresent invention. Referring to FIG. 6, the underlying networkinformation server 150 may include network information managementfunctions. The underlying network information server 150 may manageinformation about a network that the underlying network informationserver 150 belongs to, control the network according to a policy,calculate a distance between peers forming the network and provide theinformation about the network and information about the distance betweenthe peers at the request of an external entity.

The network information management server 150 may increase trafficlocality and affect the ISP when the ISP selects a peer. The underlyingnetwork information server 150 and the overlay network management server140 may interwork with each other to provide an optimal peer list by amethod in which the network information management server 150 optimizesa peer list of peers not arranged and transmits the peer list to theoverlay management server 140 or by a method in which the overlaymanagement server 140 optimizes a peer list when the network informationmanagement server 150 calculates the distance between the peersaccording to a predetermined equation and transfers the distance.

When calculating the distance between peers, the network informationmanagement server 150 may provide the distance between the peers byusing network status or policy when there is a request from the overlaymanagement server 140 or another peer 200. When a peer functions as thecache server 160, the network information management server 150 mayinteroperate with the cache server 160.

FIG. 7 is a diagram illustrating operation relationships between a peerand related entities in a peer-to-peer network according to an exemplaryembodiment of the present invention. Referring to FIG. 7, the peer 200may include such functions as peer resource management functions 210,meta information management functions 220, local profile managementfunctions 230, overlay network management peer functions 240 and peeractivity management functions 250 as functions. In addition, the peer200 may include data exchange functions 260 and buffermap managementfunctions 270 as data functions.

The peer resource management functions 210 may manage availableresources of the peer 200. Resources may include physical storage,network resource or content to be distributed through the peer-to-peernetwork. The peer resource management functions 210 may manageinformation about resources such as storage, a network and content inorder to perform a function for managing the resources of the peer 200.The information about each of the resources may include policies forresource utilization and statistics information such as resource usage.The information managed by the peer resource management functions 210may be referenced when there is a request from another entity. In thiscase, the peer resource management functions 210 may check availableresources thereof and determine whether or not to share the resources.

The meta information management 220 may manage meta information ofcontent for a network to share or transmit/receive the content.

The meta information management functions 220 may register the metainformation in the index server 130 or receive the meta information fromthe index server 130 in order to manage the meta information. The metainformation may include detailed information about the content,information about files forming the content and information about filefragments. The information about the file fragments included in the metainformation may include hash values used to check integrity to size offiles. The information about the file fragments may be used to verifythe integrity of the file fragments in the peer 200. The informationabout the content received in a fragment unit by the peer 200 may berecombined and reproduced in the peer 200.

In addition, meta information may include meta information about anoverlay network. The meta information may also include addressinformation of the overlay management server 140 for storing overlaynetwork information about the corresponding content therein and anoverlay network ID for differentiating the overlay network. The overlaynetwork ID may be a hash value of content information.

The meta information management functions 220 may further manage themeta information about the overlay network in order to manage resourcesthrough the entire overlay network in addition to the meta informationof the content according to an exemplary embodiment.

The meta information management functions 220 may perform acommunication function with the index server 130. More specifically,through communication with the index server 130, a peer may allow themeta information generated by the meta information management functions220 to be registered in the index server 130 and may receive the metainformation from the index server 130 and transmit the meta informationto the meta information management functions 220.

Local profile management functions may set and manage a user profile anda peer profile.

The user profile may include a user's ID, password and email address.

The local profile management functions 230 may set and manage a peerprofile to function as a peer in an overlay network. The peer profilemay vary depending on types of service and include an upload bandwidthpolicy, a download bandwidth policy and a maximum concurrentlysupportable peer number. The set information may be transmitted to thepeer activity management server 120.

The overlay network management peer functions 240 may manage informationabout an overlay network in which a peer is joining and informationabout peers that the overlay network management peer functions 240 cometo know.

The network management peer functions 240 may manage information aboutother peers in overlay networks that the peer is joining, morespecifically, information about overlay management servers havingoverlay network ID and information about the overlay networks. Theinformation about an overlay network may be received from the overlaymanagement server 140.

In addition, the overlay network management peer functions 240 maymanage the information about other peers in the overlay network thenetwork management peer functions 240 are joining. The information aboutother peers may be received from the overlay management server 140 orother peers. Unlike peer information received from other peers, peerinformation received from the overlay management server 140 may beoptimized by interworking between the overlay management server 140 andthe network information management server 150. The above-described twotypes of information may be separately managed.

The network management peer functions 240 may communicate with thenetwork information management server 150 in order to update peerinformation. Peer information managed by the network management peerfunctions 240 may be used for communication between peers, be separatelymanaged depending on each overlay network and include peer ID, IPaddress, port number and cost information between two peers.

The peer activity management functions 250 may be a functional entity tointerwork with other functional entities in a peer-to-peer network. Thepeer activity management functions 250 may perform communication withother entities to allow a peer to join and leave an overlay network,reserve resources, report peer status and interworking between peers.

The peer activity management functions 250 may process a message from acounterpart peer. For example, when there is a connection request fromanother peer, the peer activity management functions 250 may determinewhether or not to grant the connection request with reference toresource status information in the peer resource management functions210 and may make a response to the connection request according to aresult of the determination. In another example, when a request from acounterpart peer includes information about other peers, the peeractivity management functions 250 may transmit the information aboutother peers to the network management peer functions 240. When buffermapinformation is received from the counterpart peer, the correspondingbuffermap information may be transmitted to the buffermap managementfunctions 270 so that the buffermap management functions 270 may managethe buffermap information.

In addition, when the peer activity management functions 250 receives afragment transmission request from a peer communication clientfunctional entity of another peer, the peer activity managementfunctions 250 may interwork with the buffermap management functions 270to check a status in which the peer activity management functions 250has a fragment and may request the data exchange functions 260 totransmit the corresponding fragment if no error is found.

In addition, the peer activity management functions 250 may be in chargeof communications between peers by using a peer protocol. At this time,the peer activity management functions 250 may exchange a buffermap fordata exchange and information about other peers knowing each other byexchanging a message between peers.

In addition, when peers exchange other resources in addition to content,the peer activity management functions 250 may exchange data for sharingresources and exchange another information about peers the peer activitymanagement functions 250 know. The received peer information may betransmitted to the network management peer functions 240.

In addition, when transmitting a message to another peer, the peeractivity management functions 250 may obtain information about thecorresponding peer through the network management peer functions 240. Inaddition, when the peer activity management functions 250 transferbuffermap information thereof to another peer, the activity managementfunctions 250 may receive buffermap information from the buffermapmanagement functions 270.

In addition, when there is a fragment request of data from another peer,the peer activity management functions 250 may interwork with thebuffermap management functions 270, extract fragment information, whichthe peer activity management functions 250 need, and request a peerhaving the corresponding fragment.

The peer activity management functions 250 may communicate with theoverlay management server 140, among other entities, and control theoperation of a peer joining the overlay network. More specifically, thepeer activity management functions 250 may control peer operations, suchas joining and leaving the overlay network, and control the overlaynetwork, such as pausing and resuming a peer, in respect of services.

In addition, the peer activity management functions 250 may join acorresponding overlay network on the basis of overlay networkinformation received from the meta information management functions 220.In addition, the peer activity management functions 250 may transmitinformation about the corresponding overlay network to the overlaynetwork management peer functions 240 in order to manage the informationabout the overlay network after joining the overlay network. Inaddition, the peer activity management functions 250 may transmit thepeer list received from the overlay management server 140 to the overlaynetwork management peer functions 240.

The peer activity management functions 250 may interwork with the peeractivity management server 120 and perform a function for reporting peerinformation related to peer activity and status to the peer activitymanagement server 120. The peer information may be reported at therequest of the peer activity management server 120, or by a peer eitherperiodically or when an event occurs. In the latter case, a reportingperiod and an event may be set on the basis of policies of a serviceprovider managing P2PSP. Information about the polices of the serviceprovider may be obtained from the overlay management server 140 when thepeer joins the overlay network.

The data exchange functions 260 may be configured to exchange databetween peers. The data exchange functions 260 may transmit and receivedata and restore received content.

First, the data exchange functions 260 may transmit a data fragment ofcontent to another peer. The data exchange functions 260 may receivefragment information to be transmitted and information of a peer to bereceived from the peer activity management functions 250 and maytransmit the corresponding fragment to the peer. In addition, aftertransmitting data, the data exchange functions 260 may periodicallyreport transmission information to the peer activity management server120. When the peer transmits another information in addition to content,for example, information about the overlay network and information aboutother resources, the data exchange functions 260 may transmitcorresponding data to another peer.

In addition, the data exchange functions 260 may receive a data fragmentof content from another peer. At this time, the data exchange functions260 may check integrity of the received data fragment. To this end, hashinformation of the fragment may be obtained from the meta informationmanagement functions 220. A detailed description thereof is omittedsince it has been described in association with the meta informationmanagement functions 220. When the data exchange functions 260 receivesthe fragment of the data, the data exchange functions 260 may transmitthe fragment information to the buffermap management functions 270.

In addition, the data exchange functions 260 may combine the receivedfragments of the data received by the peer and restore these fragmentsinto original content. To this end, the data exchange functions 260 mayreceive meta information about the content from the meta informationmanagement functions 220. When the data are completely restored, thedata exchange functions 260 may report a result to the cache server 160.

The buffermap management functions 270 may perform operations related tobuffermap management in order to exchange fragments between peers inorder to perform a function for a content delivery application.

First, the buffermap management functions 270 may perform managementsuch as generating and updating buffermap information of a peer. Morespecifically, buffermap information in an entity may be updated in sucha manner that whenever the peer receives fragments of data, this isreported to the buffermap management functions 270.

In addition, when buffermap exchange is needed between peers, the peeractivity management functions 250 may request the buffermap informationfrom the buffermap management functions 270, and the buffermapinformation may be accordingly transmitted to other peers. Whenreceiving a fragment request from another peer, the peer activitymanagement functions 250 may check a status in which the buffermapmanagement functions 270 have a corresponding fragment and may transmitthe corresponding fragment through the data exchange functions 260 if noerror is found.

In addition, when receiving buffermap information from another peer, thebuffermap management functions 270 may manage and update the buffermapinformation. The buffermap information being managed may include ID ofeach peer and buffermap information received from the correspondingpeer.

In addition, at the request of the peer activity management functions250, the buffermap management functions 270 may compare local buffermapinformation with buffermap information of other peers. Morespecifically, in order to receive a data fragment, the peer activitymanagement functions 250 may request the buffermap management functions270 to compare local buffermap information thereof with the buffermapinformation of other peers, extract an index number of a fragment thatthe peer activity management functions 250 need, and transmit the indexnumber of the fragment to the peer activity management functions 250.The peer activity management functions 250 may request the correspondingfragment from a peer that has the corresponding fragment on the basis ofthis information.

FIG. 8 is a diagram illustrating interoperation relationships between anindex server and related entities in a peer-to-peer network systemaccording to an exemplary embodiment of the present invention. Referringto FIG. 8, the index server 130 may include content informationmanagement functions.

When the content information management functions manage metainformation of content, a content provider or a service provider maygenerate the meta information and register the meta information in theindex server 130. When registering the meta information, the contentprovider may input service level information about the content, forexample, content type and name in addition to the meta information. Morespecifically, the content provider may generate meta information ofcontent and enter an address of the overlay management server 140, whichwill manage an overlay network, into the meta information. The metainformation generated by the content provider may include a hash valuegenerated by using a hash function based on contents of the metainformation. This hash value may be used as an overlay ID fordifferentiating an overlay network with respect to the correspondingcontent. The content provider may be a peer or a cache server.Subsequently, the content provider may be connected to an overlaymanagement server to generate an overlay network and join the overlaynetwork.

The content information management functions may store, maintain andretrieve meta information of content. Peers may obtain meta informationabout desired content by searching service level content information,for example, name of content. When the cache server 160 operates as apeer, the cache server 160 may also obtain information about content inthe same manner as a peer does. When meta information of content isregistered, a time-out value may be set by the content provider. Themeta information of the content may be deleted after a period of timecorresponding to the time-out value.

FIG. 9 is a diagram illustrating interoperation relationships between acache server and related entities in a peer-to-peer network systemaccording to an exemplary embodiment of the present invention. Referringto FIG. 9, the cache server 160 may include cache server resourcemanagement functions 161, meta information management functions 162,resource virtualization functions 163, overlay network management peerfunctions 164, peer activity management functions 165, data exchangefunctions 166 and buffermap management functions 167.

The cache server 160 may act as a proxy in distributing or downloadingcontent for a peer.

The cache server 160 may act as a proxy in distributing content asfollows: First, the content provider may request the overlay managementserver 140 of content to act as a proxy in distributing the content. Arequest for acting as a proxy in distributing content may be made whenan overlay network is generated. Here, a content user may additionallytransmit policy information relevant to operations of the cache server160. The overlay management server 140 may reserve resources of thecache server 160 for distribution of the content and transmitcorresponding information to the content provider. The cache server 160may act as a proxy in distributing the content in such a manner that thecontent provider transmits the content to the cache server 160 by usingthe information received from the overlay management server 140. Forexample, service policy information related to operations of the cacheserver 160 may be the maximum number of seeders in a network thatmaintain the resources of the cache server 160. In other words, when thenumber of seeders in the overlay network exceeds a predetermined number,resources may be revoked since a certain amount of distribution of thecontent is ensured, and when the number of seeders is less than thepredetermined number, the resources may be maintained. The contentprovider that delegates the distribution of the content may be a peer inthe overlay network, or a content providing server or a mobile terminaloutside the overlay network.

In addition, the cache server 160 may act as a proxy in downloading thecontent. The cache server 160 may act as a proxy in downloading thecontent in a substantially similar manner as distributing the content asdescribed above. However, there is a difference between distributing anddownloading the content by proxy regarding interworking between adownload delegator, a cache server and a content distributor afterresource reservation is completed.

The cache server resource management functions 161 may perform functionssuch as a resource allocation request and resource control andmanagement of the cache server 160.

The cache server resource management functions 161 may process theresource allocation request received from the overlay management server140. When the overlay management server 140 makes a resource allocationrequest, the cache server resource management functions 161 may allocateresources and update resource status information if no error is found inthe status of resources. In addition, after the resources are allocated,the cache server resource management functions 161 may transmit policyinformation about services of resources received from the overlaymanagement server 140 to the resource virtualization functions 163 sothat the resource virtualization functions 163 may set profileinformation as a virtual peer. The cache server resource managementfunctions 161 may interwork with the meta information managementfunctions 162 and request meta information about an overlay network. Themeta information management functions 162 may receive the metainformation about the corresponding overlay network from the indexserver 130. This has been described in association with the metainformation management functions 220 of the peer. The cache server 160may join the overlay network by using the meta information of theoverlay network.

When the use of resources on the basis of the policy information about aresource service is completed, the resource virtualization functions 163may report this to the cache server resource management functions 161,and the cache server resource management functions 161 may release theallocated resources and leave the overlay network.

In addition, the cache server resource management functions 161 mayinform the overlay management server 140 of resource usage information.The overlay management server 140 may check the current status of theresources in the overlay network on the basis of the resource usageinformation and respond to requests from peers to use resources.

The cache server resource management functions 161 may manage the statusof the resources of the cache server 160, such as the total capacity andusage of storage, network or content. The cache server resourcemanagement functions 161 may inform available resources at the requestof the overlay management server 140. Since other functions of the cacheserver resource management functions 161 include operations of the peerresource management functions 210 included in the peer 200, adescription thereof is omitted.

In addition, the cache server resource management functions 161 maytransmit the resource usage information of the cache server 160 to theoverlay management server 140 in order to manage the resource usageinformation of the cache server 160. The resource usage information maybe transmitted to the user profile management server 110.

The meta information management functions 162 may perform all operationsof the meta information management functions 220 of the peer.

The meta information management functions 162 may have an inherentfunction of the cache server 160. As described above, the metainformation management functions 162 may receive meta information abouta specific overlay network from the index server 130 and allow the cacheserver 160 to join the corresponding overlay network.

Since other operations of the meta information management functions 162include the above-described operations of the meta informationmanagement functions 220 of the peer, a detailed description thereof isomitted.

The resource virtualization functions 163 may set a peer profile relatedto various operations of the cache server 160 and manage relevantinformation. More specifically, since the cache server 160 joins variousoverlay networks and operates as a content distributor or a recipient atthe request of a peer, the cache server 160 may function differently ineach overlay network. As a result, the resource virtualization functions163 may set a peer profile in respect of services to control theoperation of the cache server 160.

The resource virtualization functions 163 may perform a function forsetting a profile as a peer operating in an overlay network at therequest of the cache server resource management functions 161. Thisfunction may be substantially the same as operations of the localprofile management functions 230 included in the peer.

In addition, the resource virtualization functions 163 may manageinformation in respect of services as well as the peer profile so as tooperate as a peer in an overlay network. For example, the information inrespect of services may include service policy information of a serviceprovider in association with the cache server 160's providing andstopping service. In other words, the service provider may specifyvarious conditions associated with starting, ending and operatingservices through the information in respect of services. For example,when services are to end due to service policy, the resourcevirtualization functions 163 may inform the cache server resourcemanagement functions 161 and make a request to release the resourcesallocated to the corresponding service.

In other words, through the resource virtualization functions 163, thecache server 160 may manage a virtual peer profile and service policyinformation while the resources are allocated.

In addition, the resource virtualization functions 163 may be informedwhen the peer completely receives content. In this case, the resourcevirtualization functions 163 may update peer profile information andmake a request to release the resources if necessary.

The overlay network management peer functions 164 may manage informationabout the overlay network that the peer is joining and information aboutpeers that the overlay network management peer functions 164 come toknow. Since operations of the overlay network management peer functions164 are substantially the same as those of the network management peerfunctions 240 of the peer, a description thereof is omitted.

Since operations of the peer activity management functions 165, the dataexchange functions 166 and the buffermap management functions 167 thatconstitute the cache server 160 include operations of the functionsconstituting the peer, a description thereof is omitted.

FIG. 10 is a block diagram illustrating the configuration of a relayserver in a peer-to-peer network system according to an exemplaryembodiment of the present invention. Referring to FIG. 10, the relayserver 170 may include relay server resource management functions 171,peer activity management functions 172 and data relay functions 173.

The relay server 170 a server that improves a network connection rateand connection quality of a peer, rather than a server that activelyjoins in a peer-to-peer overlay network. Service may be provided fromthe relay server 170 by using various methods.

According to a method, when a peer that failed to join a network sincethe peer is behind a firewall transmits a network join request to theoverlay management server 140, the overlay management server 140 mayprovide the peer with resource information of the corresponding peer andthe relay server. In addition, the overlay management server 140 mayinterwork with the network information management server 150 in order toallocate resources of the relay server 170 having high accessibility tothe corresponding peer. After the allocation of the resources iscompleted, the overlay management server 140 may provide informationabout the corresponding peer to the relay server 170. The peer mayaccess the relay server 170 and generate transport mapping for datarelay. When the peer provided with the resources interworks with anotherpeer, the peer may relay data through the relay server 170. However, thepeer may report the peer activity information to the peer activitymanagement server 120 not via the relay server 170.

According to another method, when the relay server 170 includes afunction of a peer, a general peer may operate as the relay server 170.First, when the overlay management server 140 provides a peer, whichjoins a network, with a peer list, the overlay management server 140 mayalso provide information on whether or not each entity can operate asthe relay server 170. If the peer needs relay of the relay server 170when performing data transmission and reception using a peer protocol,the peer may transmit a message in which an address of a peer that canoperate the relay server 170 is included in part of the peer protocol.For example, when an address of a peer functioning as a relay server iswritten in an INT field of a header of the peer protocol, data may betransmitted to the corresponding peer, and the peer may transmit thedata to a destination peer, thereby performing a relay function. In thiscase, the corresponding peer may report activity information about thepeer functioning as the relay server 170 as peer activity information tothe peer activity management server 120. In other words, every activityinformation about a peer functioning as a relay server may be reportedas the peer activity information.

In other words, the resources provided by the relay server 170 may beprovided by the relay server 170 by control of the overlay managementserver 140 and according to the status of the resources existing in theoverlay network, or may be provided from the peer 200 that can perform arelay function according to selection of peers.

The relay server resource management functions 171 may process aresource allocation request of the relay server 170 at the request ofthe overlay management server 140 and perform functions for controllingthe resources and managing resource information.

The relay server resource management functions 171 may process theresource allocation request received from the overlay management server140. When the overlay management server 140 requests resourceallocation, the relay server resource management functions 171 may checkthe resource status, allocate the resources if no error is found in theresource status, and update the resource information provided for relay.

The relay server resource management functions 171 may maintain theresource information of the relay server 170, provided by the relayserver resource management functions 171 to the overlay network, bymanaging or updating the resource status such as total size and usage ofstorage, network or content on the basis of the provision situation.

The relay server resource management functions 171 may manage theresource usage information of the relay server 170. The resource usageinformation may be transmitted to the overlay management server 140 andthen transmitted to the user profile management server 110.

Since the function of the relay server resource management functions 171includes the operations of the peer resource management functions 210provided in the peer 200, a description thereof is omitted.

In other words, according to an exemplary embodiment of the presentinvention, since the relay server 170 relays content to a specific peerjoining an overlay network at a resource allocation request of theoverlay management server 140 and updates or maintains the resourceinformation provided for relay, a network connection rate and connectionquality of the peer may be improved.

The peer activity management functions 172 are functions for sharingdata between peers. The peer activity management functions 172 mayexchange a buffermap in advance and request a fragment in order to sharedata between peers and may include a peer protocol. The peer activitymanagement functions 172 of the relay server 170 may perform a relayfunction by using only part of the peer protocol, for example, SRC, DSTand INT fields in a message header during inter-peer communications. Asdescribed above, when the peer operates as the relay server 170, thepeer as the relay server 170 may relay content to a destination peerwith reference to the header message of the peer protocol.

Since other functions of the peer activity management functions 172include operations performed by the peer activity management functions250 of the peer, a description thereof is omitted.

The data relay functions 173 may relay data between peers under thecontrol of the peer activity management functions 172.

As set forth above, a peer-to-peer network system according to anexemplary embodiment of the present invention is described. The scope ofthe invention should not be construed as limited to the embodiments setforth herein, and may be added or modified. In addition, the scope ofthe invention should not be construed as limited to an operation and aname of a server and an operation and a name of functions constitutingthe server exemplified in the present specification. A server andfunctions constituting the server may be added, deleted or changedaccording to an exemplary embodiment.

According to the present invention, service quality may be improved byincreasing manageable functionality of a peer-to-peer network systemproviding service.

In the drawings and specification, there have been disclosed typicalexemplary embodiments of the invention and, although specific terms areemployed, they are used in a generic and descriptive sense only and notfor purposes of limitation. As for the scope of the invention, it is tobe set forth in the following claims. Therefore, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

What is claimed is:
 1. A peer-to-peer network system with manageability,comprising: at least one peer, wherein the peer-to-peer network systemprovides the at least one peer with information for configuration of apeer-to-peer network to optimize the configuration of the peer-to-peernetwork by using at least one of information about a status of the atleast one peer, information about a status of an underlying network andinformation about a user in respect of services, and the peer-to-peernetwork system allows a service provider to stably provide service tothe at least one peer.
 2. The peer-to-peer network system of claim 1,further comprising a user profile management server managing theinformation about the user in respect of services, wherein theinformation about the user in respect of services includes informationrelated to a user profile of the at least one peer or a user's serviceusage.
 3. The peer-to-peer network system of claim 1, further comprisinga peer activity management server managing the information about thestatus of the peer, wherein the information about the status of the peerincludes dynamic status information related to activity status of thepeer and peer profile information set to operate as a peer in theoverlay network.
 4. The peer-to-peer network system of claim 3, whereinthe information about the status of the peer includes informationrelated to an operation history of the peer received from the at leastone peer, or an event report.
 5. The peer-to-peer network system ofclaim 3, wherein the at least one peer provides the information aboutthe status of the peer to the peer activity management server by usingaccess information of the peer activity management server.
 6. Thepeer-to-peer network system of claim 3, wherein the peer activitymanagement server analyzes information received from the at least onepeer, generates and stores the information as peer status information,and provides the peer status information with an another entity at arequest of the another entity.
 7. The peer-to-peer network system ofclaim 6, wherein the peer activity management server transmits thestatus of the peer to the another entity at a request of the anotherentity or by a report of the peer activity management server.
 8. Thepeer-to-peer network system of claim 1, further comprising an overlaymanagement server providing the information for the configuration of thepeer-to-peer network, wherein the overlay management server managesinformation about an overlay network and information related toresources constituting the peer-to-peer network.
 9. The peer-to-peernetwork system of claim 8, wherein when receiving a request forinformation about a peer joining the overlay network from apredetermined peer, the overlay management server receives underlyingnetwork information from an another entity, receives the informationabout the status of the peer, generates an optimal peer list by usingreceived information and provides the optimal peer list to thepredetermined peer.
 10. The peer-to-peer network system of claim 8,wherein the overlay management server maintains the information relatedto the resources constituting the overlay network at a request of thepeer or another service provider and controls communication with anotherserver related to the resources or a resource requestor, and resourceallocation.
 11. The peer-to-peer network system of claim 8, furthercomprising a underlying network information server managing theunderlying network information of the peer-to-peer network and theinformation about the status of the underlying network, wherein theunderlying network information server interworks with the overlaymanagement server and generates an optimal peer list.
 12. Thepeer-to-peer network system of claim 1, wherein the peer constitutingthe peer-to-peer network manages the status of the peer and determineswhether or not to share resources at a request of another peer orserver.
 13. The peer-to-peer network system of claim 1, wherein the peermanages meta information so that content is shared in the peer-to-peernetwork.
 14. The peer-to-peer network system of claim 13, wherein themeta information includes meta information of the content and metainformation about an overlay network.
 15. The peer-to-peer networksystem of claim 1, wherein the at least one peer performs communicationbetween peers and transmits/receives at least one of buffermapinformation, content data and another peer information.
 16. Thepeer-to-peer network system of claim 14, wherein the at least one peerjoins the overlay network by using the meta information, checksintegrity of the content and restores the content by using the metainformation.
 17. The peer-to-peer network system of claim 1, furthercomprising an index server registering and managing meta information ofcontent maintained or shared in an overlay network.
 18. The peer-to-peernetwork system of claim 17, wherein the index server manages the metainformation of the content along with service-level content informationinput by the user.
 19. The peer-to-peer network system of claim 1,further comprising a cache server providing resources for distributingor downloading content shared in an overlay network by proxy.
 20. Thepeer-to-peer network system of claim 19, wherein the resources providedby the cache server are maintained on the basis of policy information ofthe overlay network.